Liquid crystal composition and liquid crystal display device

ABSTRACT

A liquid crystal composition having a negative dielectric anisotropy that includes three components, wherein the first component is at least one compound selected from the group of compounds represented by Formulas (1-1) to (1-6), the second component is at least one compound selected from the group of compounds represented by Formula (2), and the third component is at least one compound selected from the group of compounds represented by Formulas (3-1) and (3-2): 
     
       
         
         
             
             
         
       
     
     wherein, for example, R 1 , R 2 , R 3 , R 4  and R 5  are alkyl having 1 to 12 carbons; X 1  and X 2  are fluorine; Z 1 , Z 2 , Z 3 , Z 4 , Z 5  and Z 6  are a single bond; and ring A, ring B, ring C and ring D are 1,4-cyclohexylene or 1,4-phenylene.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 119 to JapanesePatent Application No. JP 2006-218213, filed Aug. 10, 2006, which isexpressly incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a liquid crystal composition suitable for usein an active matrix (AM) device, and an AM device containing thecomposition. In particular, the invention relates to a liquid crystalcomposition having a negative dielectric anisotropy, and to a devicehaving an IPS (in-plane switching) mode or a VA (vertical alignment)mode containing the composition.

2. Related Art

In a liquid crystal display device, classification based on an operatingmode of liquid crystals includes phase change (PC), twisted nematic(TN), super twisted nematic (STN), electrically controlled birefiingence(ECB), optically compensated bend (OCB), in-plane switching (IPS),vertical alignment (VA), and so forth. Classification based on a drivingmode includes a passive matrix (PM) and an active matrix (AM). PM isfurther classified into static, multiplex and so forth, and AM isclassified into a thin film transistor (TFT), a metal insulator metal(IM) and so forth. TFT is further classified into amorphous silicon andpolycrystal silicon. The latter is classified into a high temperaturetype and a low temperature type according to a production process.Classification based on a light source includes a reflection typeutilizing a natural light, a transmission type utilizing a backlight anda semi-transmission type utilizing both the natural light and thebacklight.

These devices contain a liquid crystal composition having suitablecharacteristics. The liquid crystal composition has a nematic phase.General characteristics of the composition should be improved to obtainan AM device having good general characteristics. Table 1 belowsummarizes the relationship between the general characteristics of thetwo. The general characteristics of the composition will be explainedfurther based on a commercially available AM device. A temperature rangeof a nematic phase relates to the temperature range in which the devicecan be used. A desirable maximum temperature of the nematic phase isapproximately 70° C. or more and a desirable minimum temperature isapproximately −10° C. or less. The viscosity of the composition relatesto the response time of the device. A short response time is desirablefor displaying a moving image. Accordingly, a small viscosity of thecomposition is desirable. A small viscosity at a low temperature is moredesirable.

TABLE 1 General Characteristics of a Liquid Crystal Composition and anAM Device General Characteristics No General Characteristics of aComposition of an AM Device 1 Temperature range of a nematic phase isUsable temperature wide range is wide 2 Viscosity is small¹⁾ Responsetime is short 3 Optical anisotropy is suitable Contrast ratio is large 4Dielectric anisotropy is large Threshold voltage is low, electric powerconsumption is small, and a contrast ratio is large 5 Specificresistance is large Voltage holding ratio is large and a contrast ratiois large 6 It is stable to ultraviolet light and heat Service life islong ¹⁾A liquid crystal composition can be injected into a cell in ashort time.

The optical anisotropy of the composition relates to the contrast ratioof the device. Devices having a VA mode, an IPS mode, and so forthutilize electrically controlled birefringence. In order to maximize thecontrast ratio of a device having a VA mode, an IPS mode, and so forth,a product (Δn·d) of the optical anisotropy (Δn) of the composition andthe cell gap (d) of the device is designed to be a constant value.Examples of the value include from approximately 0.30 to approximately0.40 μm (VA mode) and from approximately 0.20 to approximately 0.30 μm(IPS mode). Since the celi gap (d) is generally from approximately 2 toapproximately 6 μm, the optical anisotropy of the composition isgenerally from approximately 0.05 to approximately 0.16. A largedielectric anisotropy of the composition contributes to a low thresholdvoltage, a small electric power consumption and a large contrast ratioof the device. Accordingly, a low threshold voltage is desirable. Alarge specific resistance of the composition contributes to a largevoltage holding ratio and a large contrast ratio of the device.Accordingly, a composition having a large specific resistance isdesirable at room temperature and also at a high temperature in theinitial stage. A composition having a large specific resistance at roomtemperature and also at a high temperature after it has been used for along time. The stability to an ultraviolet ray and heat of thecomposition relates to the service life of the device. The service lifeof the device is long when the stability is high. These characteristicsare preferred for an AM device used for a liquid crystal projector, aliquid crystal television and so forth.

A composition having a positive dielectric anisotropy is used in an AMdevice having a TN mode. A composition having a negative dielectricanisotropy is used in an AM device having a VA mode. A compositionhaving a positive or negative dielectric anisotropy is used in an AMdevice having an IPS mode. Examples of a liquid crystal compositionhaving a negative dielectric anisotropy are disclosed in the followingpatent documents: JP H8-104869 A/1996, JP H10-176167 A/1998, JPH11-140447 A/1999, JP 2001-354967 A/2001 and WO 2006-038522 A/2006.

A desirable AM device is characterized as having a usable temperaturerange that is wide, a response time that is short, a contrast ratio thatis large, a threshold voltage that is low, a voltage holding ratio thatis large, a service life that is long, and so forth. Even a onemillisecond shorter response time is desirable. Thus, the compositionhaving characteristics such as a high maximum temperature of a nematicphase, a low minimum temperature of a nematic phase, a small viscosity,a large optical anisotropy, a negatively large dielectric anisotropy, alarge specific resistance, a high stability to an ultraviolet light, ahigh stability to heat, and so forth is especially desirable.

SUMMARY OF THE INVENTION

The invention relates to a liquid crystal composition having a negativedielectric anisotropy that includes three components, wherein the firstcomponent is at least one compound selected from the group of compoundsrepresented by Formulas (1-1) to (1-6), the second component is at leastone compound selected from the group of compounds represented by Formula(2), and the third component is at least one compound selected from thegroup of compounds represented by Formulas (3-1) and (3-2):

wherein R¹ and R² are each independently alkyl having 1 to 12 carbons,alkoxy having from 1 to 12 carbons, alkenyl having 2 to 12 carbons oralkenyl having 2 to 12 carbons, arbitrary hydrogen of which are replacedby fluorine; R³ to R⁵ are each independently alkyl having 1 to 12carbons, alkoxy having from 1 to 12 carbons, alkenyl having 2 to 12carbons or alkenyl having 2 to 12 carbons, arbitrary hydrogen of whichare replaced by fluorine; X¹ and X² are each independently fluorine orchlorine, provided that at least one of X¹ and X² is fluorine; Z¹ and Z²are each independently a single bond, —CH₂CH₂— or —CH═CH—; Z³ to Z⁶ areeach independently a single bond or —CH₂CH₂—; and ring A, ring B, ring Cand ring D are each independently 1,4-cyclohexylene or 1,4-phenylene.

DETAILED DESCRIPTION OF THE INVENTION

The terms used in the specification and claims are defined as follows.The liquid crystal composition and/or the liquid crystal display deviceof the invention may occasionally be expressed simply as “thecomposition” or “the device,” respectively. A liquid crystal displaydevice is a generic term for a liquid crystal display panel and a liquidcrystal display module. The “liquid crystal compound” is a generic termfor a compound having a liquid crystal phase such as a nematic phase, asmectic phase and so forth, and also for a compound having no liquidcrystal phase but being useful as a component of a composition. Theuseful compound contains a 6-membered ring such as 1,4-cyclohexylene and1,4-phenylene, and a rod-like molecular structure. An optically activecompound may occasionally be added to the composition. Even in the casewhere the compound is a liquid crystal compound, the compound isclassified into an additive. At least one compound selected from a groupof compounds represented by Formula (1-1) may be abbreviated to “thecompound (1-1).” The term “the compound (1-1)” means one compound or twoor more compounds represented by Formula (1-1). The other formulas areapplied with the same rules. The term “arbitrary” means not only anarbitrary position but also an arbitrary number, and the case where thenumber is zero is not included.

A higher limit of a temperature range of a nematic phase may beabbreviated to “a maximum temperature.” A lower limit of a temperaturerange of a nematic phase may be abbreviated to “a minimum temperature.”“A specific resistance is large” means that the composition has a largespecific resistance at room temperature and also at a high temperaturein the initial stage, the composition has a large specific resistance atroom temperature and also at a high temperature even after it has beenused for a long time. “A voltage holding ratio is large” means that adevice has a large voltage holding ratio at room temperature and also ata high temperature in the initial stage, the device has a large voltageholding ratio at room temperature and also at a high temperature evenafter it has been used for a long time. In the description of thecharacteristics, such as optical anisotropy, the characteristics of thecomposition such as the optical anisotropy and so forth are valuesmeasured in the methods disclosed in Examples. The first component isone compound or two or more compounds. “A ratio of the first component”means the percentage by weight (% by weight) based on the total weightof liquid crystal composition. A ratio of the second component and soforth are applied with the same rule. A ratio of an additive mixed withthe composition means the percentage by weight (% by weight) based onthe total weight of liquid crystal composition.

The symbol R¹ is used for many compounds in the chemical formulas forthe component compounds. R¹ may be identical or different in thesecompounds. In one case, for example, R¹ of the compound (1-1) is ethyland R¹ of the compound (1-2) is ethyl. In another case, R¹ of thecompound (1-1) is ethyl and R¹ of the compound (1-2) is propyl. Thisrule is also applicable to the symbols R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹,R¹⁰, R¹¹ and so forth.

One of the advantages of the invention is to provide a liquid crystalcomposition that satisfies many characteristics among thecharacteristics such as a high maximum temperature of a nematic phase, alow minimum temperature of a nematic phase, a small viscosity, asuitable optical anisotropy, a negatively large dielectric anisotropy, alarge specific resistance, a high stability to ultraviolet light, a highstability to heat and so forth, and particularly, a liquid crystalcomposition excellent in three characteristics including a high miaximumtemperature of a nematic phase, a low minimum temperature of a nematicphase and a negatively large dielectric anisotropy. Another of theadvantages of the invention is to provide a liquid crystal compositionthat is properly balanced regarding at least two characteristics amongthe many characteristics. Another of the advantages of the invention isto provide a liquid crystal display device that contains the liquidcrystal composition. One aspect of the invention is to provide a liquidcrystal composition that has a high maximum temperature of a nematicphase, a low minimum temperature of a nematic phase, a suitable opticalanisotropy, a negatively large dielectric anisotropy, a small viscosityand so forth, and is to provide an AM device that has a wide operationtemperature range, a large contrast ratio, a low threshold voltage, ashort response time, a large voltage holding ratio, a long service lifeand so forth.

The Invention Includes:

1. A liquid crystal composition having a negative dielectric anisotropyincluding three components, wherein the first component is at least onecompound selected from the group of compounds represented by Formulas(1-1) to (1-6), the second component is at least one compound selectedfrom the group of compounds represented by Formula (2), and the thirdcomponent is at least one compound selected from the group of compoundsrepresented by Formulas (3-1) and (3-2):

wherein R¹ and R² are each independently alkyl having 1 to 12 carbons,alkoxy having from 1 to 12 carbons, alkenyl having 2 to 12 carbons oralkenyl having 2 to 12 carbons, arbitrary hydrogen of which are replacedby fluorine; R³ to R⁵ are each independently alkyl having 1 to 12carbons, alkoxy having from 1 to 12 carbons, alkenyl having 2 to 12carbons or alkenyl having 2 to 12 carbons, arbitrary hydrogen of whichare replaced by fluorine; X¹ and X² are each independently fluorine orchlorine, provided that at least one of X¹ and X² is fluorine; Z¹ and Z²are each independently a single bond, —CH₂CH₂— or —CH═CH—; Z³ to Z⁶ areeach independently a single bond or —CH₂CH₂—; and ring A, ring B, ring Cand ring D are each independently 1,4-cyclohexylene or 1,4-phenylene.

2. The liquid crystal composition according to item 1, wherein the firstcomponent is at least one compound selected from the group of compoundsrepresented by Formulas (1-1) and (1-2), and the third component is atleast one compound selected from the group of compounds represented byFormula (3-1).

3. The liquid crystal composition according to item 1, wherein the firstcomponent is at least one compound selected from the group of compoundsrepresented by Formulas (1-3) to (1-6), and the third component is atleast one compound selected from the group of compounds represented byFormula (3-1).

4. The liquid crystal composition according to any one of items 1 to 3,wherein the ratio of the first component is from approximately 10% byweight to approximately 40% by weight, the ratio of the second componentis from approximately 15% by weight to approximately 40% by weight, andthe ratio of the third component is from approximately 20% by weight toapproximately 50% by weight, based on the total weight of the liquidcrystal composition.

5. A liquid crystal composition having a negative dielectric anisotropyincluding three components, wherein the first component is at least onecompound selected from the group of compounds represented by Formulas(1-1-A) to (1-6-A), the second component is at least one compoundselected from the group of compounds represented by Formula (2-A), andthe third component is at least one compound selected from the group ofcompounds represented by Formulas (3-1-A) and (3-2-A):

wherein R¹ and R² are each independently alkyl having 1 to 12 carbons,alkoxy having from 1 to 12 carbons, alkenyl having 2 to 12 carbons oralkenyl having 2 to 12 carbons, arbitrary hydrogen of which are replacedby fluorine; R³ to R⁵ are each independently alkyl having 1 to 12carbons, alkoxy having from 1 to 12 carbons, alkenyl having 2 to 12carbons or alkenyl having 2 to 12 carbons, arbitrary hydrogen of whichare replaced by fluorine; Z¹ is a single bond, —CH₂CH₂— or —CH═CH—; Z³and Z⁴ are each independently a single bond or —CH₂CH₂—; and ring B andring D are each independently 1,4-cyclohexylene or 1,4-phenylene.

6. The liquid crystal composition according to item 5, wherein thesecond component is at least one compound selected from the group ofcompounds represented by Formula (2-A); in Formula (2-A), R³ is alkylhaving 1 to 12 carbons or alkenyl having 2 to 12 carbons, and R⁴ isalkoxy having 1 to 12 carbons; in Formula (3-1-A), R³ is alkyl having 1to 12 carbons or alkenyl having 2 to 12 carbons, R⁴ is alkoxy having 1to 2 carbons; and in Formula (3-2-A), R³ and R⁵ are each independentlyalkyl having 1 to 12 carbons.

7. The liquid crystal composition according to item 6, wherein inFormulas (1-1-A) to (1-6-A), Z¹ is a single bond, one of R¹ and R² isalkyl having 1 to 12 carbons, and the other is alkenyl having 2 to 12carbons.

8. The liquid crystal composition according to item 7, wherein the firstcomponent is at least one compound selected from the group of compoundsrepresented by Formulas (1-1-A) and (1-2-A), and the third component isat least one compound selected from the group of compounds representedby Formula (3-1-A).

9. The liquid crystal composition according to item 7, wherein the firstcomponent is at least one compound selected from the group of compoundsrepresented by Formulas (1-3-A) to (1-6-A), and the third component isat least one compound selected from the group of compounds representedby Formula (3-1-A).

10. The liquid crystal composition according to item 7, wherein thefirst component is a mixture of at least one compound selected from thegroup of compounds represented by Formulas (1-1-A) and (1-2-A) and atleast one compound selected from the group of compounds represented byFormulas (1-3-A) to (1-6-A), and the third component is at least onecompound selected from the group of compounds represented by Formula(3-1-A).

11. The liquid crystal composition according to any one of items 5 to10, wherein the ratio of the first component is from approximately 10%by weight to approximately 40% by weight, the ratio of the secondcomponent is from approximately 15% by weight to approximately 40% byweight, and the ratio of the third component is from approximately 20%by weight to approximately 50% by weight, based on the total weight ofthe liquid crystal composition.

12. The liquid crystal composition according to any one of items 5 to11, wherein the composition further includes at least one compoundselected from the group of compounds represented by Formulas (4-1-A) to(4-4-A) as a fourth component:

wherein R⁶ to R¹¹ are each independently alkyl having 1 to 12 carbons,alkoxy having from 1 to 12 carbons, alkenyl having 2 to 12 carbons oralkenyl having 2 to 12 carbons, arbitrary hydrogen of which are replacedby fluorine; X³, X⁴ and X⁵ are each independently fluorine or hydrogen,provided that at least one of X³, X⁴ and X⁵ is fluorine; and Z⁷ is —COO—or —CH₂O—.

13. The liquid crystal composition according to item 12, wherein inFormula (4-1-A), R⁶ and R⁷ are alkyl having 1 to 12 carbons, and Z⁷ is—COO—; in Formulas (4-2-A) and (4-3-A), R⁸ is alkenyl having 2 to 12carbons, and R⁹ is alkyl having 1 to 12 carbons; and in Formula (4-4-A),R¹⁰ and R¹¹ are each independently alkyl having 1 to 12 carbons oralkenyl having 2 to 12 carbons, X³ is fluorine, and X⁴ and X⁵ arehydrogen.

14. The liquid crystal composition according to item 12 or 13, whereinthe fourth component is at least one compound selected from the group ofcompounds represented by Formula (4-2-A).

15. The liquid crystal composition according to item 12 or 13, whereinthe fourth component is at least one compound selected from the group ofcompounds represented by Formula (4-4-A).

16. The liquid crystal composition according to any one of items 12 to15, wherein the ratio of the first component is from approximately 10%by weight to approximately 40% by weight, the ratio of the secondcomponent is from approximately 15% by weight to approximately 40% byweight, the ratio of the third component is from approximately 20% byweight to approximately 50% by weight, and the ratio of the fourthcomponent is from approximately 5% by weight to approximately 30% byweight, based on the total weight of the liquid crystal composition.

17. The liquid crystal composition according to any one of items 1 to16, wherein the composition has a maximum temperature of a nematic phaseof approximately 70° C. or more, a dielectric anisotropy (25° C.) at afrequency of 1 kHz of from approximately −6.0 to approximately −3.0, anda refractive index anisotropy (25° C.) at a wavelength of 589 nm of fromapproximately 0.08 to approximately 0.13.

18. A liquid display device that includes the liquid crystal compositionaccording to any one of items 1 to 17.

19. The liquid crystal display device according to item 18, wherein theliquid crystal display device has an operation mode of a VA mode or anIPS mode, and has a driving mode of an active matrix mode.

The invention further includes: (1) the composition described above,wherein the composition further contains an optically active compound;(2) the composition described above, wherein the composition furtherincludes an additive, such as an antioxidant, an ultraviolet lightabsorbent and/or a defoaming agent; (3) an AM device including thecomposition described above; (4) a device having an IPS or VA mode,includings the composition described above; (5) a device of atransmission type, including the composition described above; (6) use ofthe composition described above as a composition having a nematic phase;and (7) use as an optically active composition by adding an opticallyactive compound to the composition described above.

The composition of the invention will be explained in the followingorder. First, the constitution of component compounds in the compositionwill be explained. Second, the main characteristics of the componentcompounds and the main effects of the compounds on the composition willbe explained. Third, a desirable ratio of the component compounds andthe basis thereof will be explained. Fourth, a desirable embodiment ofthe component compounds will be explained. Fifth, examples of thecomponent compound will be shown. Sixth, additives that may be added tothe composition will be explained. Seventh, the preparation methods ofthe component compound will be explained. Lastly, use of the compositionwill be explained.

First, the constitution of component compounds in the composition willbe explained. The composition of the invention is classified into thecomposition A and the composition B. The composition A may furthercontain a liquid crystal compound, an additive, an impurity, and soforth. This liquid crystal compound is different from the compound(1-1), the compound (1-2), the compound (1-3), the compound (1-4), thecompound (1-5), the compound (1-6), the compound (2), the compound(3-1), the compound (3-2), the compound (4-1-A), the compound (4-2-A),the compound (4-3-A) and the compound (4-4-A). Such a compound is mixedwith the composition for the purpose of adjusting the characteristics ofthe composition. Among the liquid crystal compounds, an amount of acyano compound is desirably small from the viewpoint of stability toheat or ultraviolet light. A further preferred ratio of the cyanocompound is 0% by weight. The additive includes an optically activecompound, an antioxidant, an ultraviolet light absorbent, a coloringmatter, a defoaming agent and so forth. The impurity is a compound andso forth contaminated in the process such as the synthesis of acomponent compound and so forth.

The composition B essentially consists of the compounds selected fromthe compound (1-1), the compound (1-2), the compound (1-3), the compound(1-4), the compound (1-5), the compound (1-6), the compound (2), thecompound (3-1), the compound (3-2), the compound (4-1-A), the compound(4-2-A), the compound (4-3-A) and the compound (4-4-A). The term“essentially” means that the composition does not contain a liquidcrystal compound which is different from these compounds. The term“essentially” also means that the composition may further contain theadditive, the impurity, and so forth. The components of the compositionB are fewer than those of the composition A. The composition B ispreferable to the composition A from the viewpoint of costs. Thecomposition A is preferable to the composition B, becausecharacteristics of the composition A can be further adjusted by mixingwith other liquid crystal compounds.

Second, the main characteristics of the component compounds and the maineffects of the compounds on the composition will be explained. The maincharacteristics of the component compounds are summarized in Table 2according to the advantages of the invention. In Table 2, the symbol Lrepresents large or high, the symbol M represents a middle degree, andthe symbol S represents small or low. The symbols L, M and S areclassification based on qualitative comparison among the componentcompound.

TABLE 2 Characteristics of Compounds Compound (1-1) and (1-3) to (1-2)(1-6) (2) (3-1) (3-2) (4-1-A) (4-2-A) (4-3-A) (4-4-A) Maximum M L S L LL L L L temperature Viscosity S M M L L M M M M Optical S M M M L S M ML anisotropy Dielectric M¹⁾ M¹⁾ L¹⁾ L¹⁾ L¹⁾ S S S S anisotropy SpecificL L L L L L L L L resistance ¹⁾The dielectric anisotropy is negative,and the symbol shows magnitude of an absolute value.

The main effects of the component compounds to the characteristics ofthe composition upon mixing the component compounds to the compositionare as follows. The compounds (1-1) and (1-2) increase the absolutevalue of the dielectric anisotropy, decrease the viscosity, anddecreases the minimum temperature. The compounds (1-3) to (1-6) increasethe absolute value of the dielectric anisotropy, increases the maximumtemperature, decrease the viscosity, and decreases the minimumtemperature. The compound (2) increases the absolute value of thedielectric anisotropy. The compounds (3-1) and (3-2) increase theabsolute value of the dielectric anisotropy and increase the maximumtemperature. The compounds (4-1-A), (4-2-A), (4-3-A) and (4-4-A)increase the maximum temperature, decrease the viscosity, and controlsthe refractive index anisotropy depending on the contents of thecompounds.

Third, desirable ratios of the component compounds and the basistherefor will be explained. A desirable ratio of the first component isapproximately 10% by weight or more for increasing the absolute value ofthe dielectric anisotropy, decreasing the minimum temperature, anddecreasing the viscosity, and is approximately 40% by weight or less fordecreasing the minimum temperature. A more desirable ratio is fromapproximately 10% by weight to approximately 35% by weight. Aparticularly desirable ratio is from approximately 10% to approximately30%.

A desirable ratio of the second component is approximately 15% by weightor more for increasing the absolute value of the dielectric anisotropy,and is approximately 40% by weight or less for increasing the maximumtemperature and decreasing the minimum temperature. A more desirableratio is from approximately 20% by weight to approximately 40% byweight. A particularly desirable ratio is from approximately 20% byweight to approximately 30% by weight.

A desirable ratio of the third component is approximately 20% by weightor more for increasing the absolute value of the dielectric anisotropyand increasing the maximum temperature, and is approximately 50% byweight or less for decreasing the viscosity and decreasing the minimumtemperature. A more desirable ratio is from approximately 25% by weightto approximately 50% by weight. A particularly desirable ratio is fromapproximately 30% by weight to approximately 50% by weight.

The fourth component is suitable for preparing a composition having aparticularly small viscosity. A desirable ratio of the fourth componentis from approximately 5% by weight to approximately 30% by weight. Amore desirable ratio is from approximately 5% by weight to approximately25% by weight. A particularly desirable ratio is from approximately 5%by weight to approximately 20% by weight.

In the composition A, a desirable total ratio of the first component,the second component, the third component and the fourth component isapproximately 70% by weight or more for obtaining good characteristics.A more desirable total ratio is approximately 90% by weight or more. Inthe composition B described above, a total ratio of the four componentsis 100% by weight.

Fourth, a desirable embodiment of the component compound will beexplained. R¹ and R² are each independently alkyl having 1 to 12carbons, alkoxy having from 1 to 12 carbons, alkenyl having 2 to 12carbons or alkenyl having 2 to 12, carbons, arbitrary hydrogen of whichare replaced by fluorine. Desirable R¹ and R² are linear alkyl having 1to 8 carbons, linear alkenyl having 2 to 8 carbons and linear alkenylhaving 2 to 8 carbons, arbitrary hydrogen of which are replaced byfluorine, for increasing the maximum temperature, decreasing the minimumtemperature, and decreasing the viscosity. More desirable R¹ and R² aresuch combinations that one of R¹ and R² is linear alkyl having 1 to 8carbons, and the other is linear alkenyl having 2 to 8 carbons. R³ to R⁵are each independently alkyl having 1 to 12 carbons, alkoxy having from1 to 12 carbons, alkenyl having 2 to 12 carbons or alkenyl having 2 to12 carbons, arbitrary hydrogen of which are replaced by fluorine.Desirable R³ is linear alkyl having 1 to 8 carbons, linear alkenylhaving 2 to 8 carbons and linear alkenyl having 2 to 8 carbons,arbitrary hydrogen of which is replaced by fluorine, for increasing themaximum temperature and decreasing the viscosity. More desirable R³ islinear alkyl having 1 to 8 carbons and linear alkenyl having 2 to 8carbons. Desirable R⁴ is linear alkyl having 1 to 12 carbons and linearalkoxy having 1 to 12 carbons for increasing the absolute value of thedielectric anisotropy. More desirable R⁴ is linear alkoxy having 1 to 8carbons. Particularly desirable R⁴: is linear alkoxy having 1 to 4carbons. Desirable R⁵ is linear alkyl having 1 to 8 carbons, linearalkenyl having 2 to 8 carbons and linear alkenyl having 2 to 8 carbons,arbitrary hydrogen of which are replaced by fluorine, for increasing themaximum temperature and decreasing the viscosity. More desirable R⁵ islinear alkyl having 1 to 8 carbons and linear alkenyl having 2 to 8carbons. Particularly desirable R⁵ is linear alkyl having 1 to 8carbons. R⁶ to R¹¹ are each independently alkyl having 1 to 12 carbons,alkoxy having from 1 to 12 carbons, alkenyl having 2 to 12 carbons oralkenyl having 2 to 12 carbons, arbitrary hydrogen of which are replacedby fluorine. Desirable R⁶ and R⁷ are linear alkyl having 1 to 8 carbons,linear alkenyl having 2 to 8 carbons and linear alkenyl having 2 to 8carbons, arbitrary hydrogen of which is replaced by fluorine, forincreasing the maximum temperature and decreasing the viscosity. Moredesirable R⁶ and R⁷ are linear alkyl having 1 to 5 carbons and linearalkenyl having 2 to 5 carbons. Particularly desirable R⁶ and R⁷ arelinear alkyl having 1 to 5 carbons. Desirable R⁸ is linear alkyl having1 to 12 carbons, linear alkenyl having 2 to 12 carbons and linearalkenyl having 2 to 12 carbons, arbitrary hydrogen of which are replacedby fluorine, for increasing the maximum temperature, decreasing theminimum temperature, and decreasing the viscosity. More desirable R⁸ islinear alkyl having 1 to 12 carbons and linear alkenyl having 2 to 12carbons. Particularly desirable R⁸ is linear alkenyl having 2 to 12carbons. Desirable R⁹ is linear alkyl having 1 to 12 carbons or linearalkoxy having 1 to 12 carbons for increasing the maximum temperature,decreasing the minimum temperature, and decreasing the viscosity. Moredesirable R⁹ is linear alkyl having 1 to 5 carbons. Desirable R¹⁰ andR¹¹ are linear alkyl having 1 to 12 carbons and linear alkenyl having 2to 12 carbons for increasing the maximum temperature, decreasing theminimum temperature, and decreasing the viscosity. More desirable R¹⁰and R¹¹ are linear alkyl having 1 to 5 carbons and linear alkenyl having2 to 5 carbons.

Desirable alkyl is methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl,or octyl. More desirable alkyl is ethyl, propyl, butyl, pentyl, orheptyl for decreasing the viscosity.

Desirable alkoxy is methoxy, ethoxy, propoxy, butoxy, pentyloxy,hexyloxy, or heptyloxy. More desirable alkoxy is methoxy or ethoxy fordecreasing the viscosity.

Desirable alkenyl is vinyl, 1-propenyl, 2-propenyl, 1-butenyl,2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl,1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, or 5-hexenyl. More desirablealkenyl is vinyl, 1-propenyl, 3-butenyl, or 3-pentenyl for decreasingthe viscosity. A desirable configuration of —CH═CH— in these alkenylsdepends on the position of a double bond. Trans is desirable in thealkenyl such as 1-propenyl, 1-butenyl, 1-pentenyl, 1-hexenyl,3-pentenyl, and 3-hexenyl for decreasing the viscosity. Cis is desirablein the alkenyl such as 2-butenyl, 2-pentenyl and 2-hexenyl. In thesealkenyls, linear alkenyl is preferable to branched alkenyl.

Preferred examples of alkenyl, arbitrary hydrogen of which is replacedby fluorine, include 2,2-difluorovinyl, 3,3-difluoro-2-propenyl,4,4-difluoro-3-butenyl, 5,5-difluoro-4-pentenyl and6,6-difluoro-5-hexenyl. More preferred examples thereof include2,2-difluorovinyl and 4,4-difluoro-3-butenyl for decreasing theviscosity.

Ring A, ring B, ring C and ring D are each independently1,4-cyclohexylene or 1,4-phenylene. Desirable ring A is1,4-cyclohexylene for increasing the maximum temperature, decreasing theminimum temperature, and decreasing the viscosity. Desirable ring B is1,4-phenylene in the case where a large refractive index anisotropy isdemanded, and is 1,4-cyclohexylene in the case where a small refractiveindex anisotropy is demanded. Desirable ring C is 1,4-cyclohexylene and1,4-phenylene for increasing an absolute value of the dielectricanisotropy. Desirable ring D is 1,4-cyclohexylene and 1,4-phenylene forincreasing an absolute value of the dielectric anisotropy. On theconfiguration of 1,4-cyclohexylene in the compounds, trans is preferableto cis for increasing the maximum temperature.

Z¹ and Z² are each independently a single bond, —CH₂CH₂— or —CH═CH—.Desirable Z¹ and Z2 are a single bond for decreasing the minimumtemperature and decreasing the viscosity. Z³ to Z⁶ are eachindependently a single bond or —CH₂CH₂—. Desirable Z³ is a single bondand —CH₂CH₂— for increasing the absolute value of the dielectricanisotropy. More desirable Z³ is a single bond. Desirable Z⁴ is a singlebond for decreasing the minimum temperature. Desirable Z⁵ and Z⁶ are asingle bond for decreasing the viscosity. Z⁷ is —COO— or —CH₂O—.Desirable Z⁷ is —COO— for decreasing the minimum temperature.

X¹ and X² are each independently fluorine or chlorine, provided that atleast one of X¹ and X²is fluorine. Desirable X¹ is fluorine forincreasing the absolute value of the dielectric anisotropy. Desirable X²is fluorine or chlorine for increasing the absolute value of thedielectric anisotropy. Desirable X² is fluorine. X³, X⁴ and X⁵ are eachindependently fluorine or hydrogen, provided that at least one of X³, X⁴and X⁵ is fluorine. Desirable combinations of X³, X⁴ and X⁵ are acombination of fluorine, hydrogen and hydrogen, a combination ofhydrogen, fluorine and hydrogen, and a combination of fluorine, hydrogenand fluorine, in this order, for increasing the maximum temperature,decreasing the minimum temperature, and decreasing the viscosity. A moredesirable combination of X³, X⁴ and X⁵ is a combination of fluorine,hydrogen and hydrogen in this order.

Fifth, examples of the component compound will be shown. In thedesirable compounds described below, R¹² is linear alkyl having 1 to 12carbons, R¹³ is linear alkyl having 1 to 12 carbons or linear alkoxyhaving 1 to 12 carbons, and R¹⁴ is linear alkenyl having 2 to 12 carbonsor linear alkenyl having 2 to 12 carbons, arbitrary hydrogen of whichare replaced by fluorine. R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R¹⁰ and R¹¹ havethe same meanings as above. In these compounds, trans is preferable tocis for the configuration of 1,4-cyclohexylene for increasing themaximum temperature.

Desirable compounds (1-1) are the compounds (1-1-1) to (1-1-6). A moredesirable compound (1-1) is the compound (1-1-1). Desirable compounds(1-2) are the compounds (1-2-1) to (1-2-6). A more desirable compound(1-2) is the compound (1-2-1). Desirable compounds (1-3) are thecompounds (1-3-1) to (1-3-7). More desirable compounds (1-3) are thecompounds (1-3-1) and (1-3-5). Desirable compounds (1-4) are thecompounds (1-4-1) to (1-4-7). More desirable compounds (1-4) are thecompounds (1-4-1) and (1-4-5). Desirable compounds (1-5) are thecompounds (1-5-1) to (1-5-4). A more desirable compound (1-5) is thecompound (1-5-1). Desirable compounds (1-6) are the compounds (1-6-1) to(1-6-4). A more desirable compound (1-6) is the compound (1-6-1). Forthe first component, the compounds (1-1) and (1-2) are desirable to thecompounds (1-3) to (1-6) from the standpoint of a negatively lowdielectric anisotropy and a low minimum temperature. Desirable compounds(2) are the compounds (2-1) to (2-6). More desirable compounds (2) arethe compounds (2-1), (2-2) and (2-3). A particularly desirable compound(2) is the compound (2-1). Desirable compounds (3-1) are the compounds(3-1-1 to (3-1-18). More desirable compounds (3-1) are the compounds(3-1-1), (3-1-2), (3-1-4), (3-1-7) and (3-1-10). Particularly desirablecompounds (3-1) are the compounds (3-1-1) and (3-1-4). Desirablecompounds (3-2) are the compounds (3-2-1) to (3-2-7). A more desirablecompound (3-2) is the compound (3-2-1). Desirable compounds (4-1-A) arethe compounds (4-1-1) and (4-1-2). A more desirable compound (4-1-A) isthe compound (4-1-1). Desirable compounds (4-2-A) are the compounds(4-2-1) and (4-2-2). A more desirable compound (4-2-A) is the compound(4-2-2). Desirable compounds (4-3-A) are the compounds (4-3-1) and(4-3-2). A more desirable compound (4-3-A) is the compound (4-3-2).Desirable compounds (4-4-A) are the compounds (4-4-1) to (4-4-3). A moredesirable compound (4-4-A) is the compound (4-4-1).

Sixth, additives capable of being mixed with the composition will beexplained. The additives include an optically active compound, anantioxidant, an ultraviolet light absorbent, a coloring matter, adefoaming agent and so forth. An optically active compound is mixed inthe composition for inducing a helical structure of liquid crystal toprovide a twist angle. Examples of the optically active compound includethe compounds (5-1) to (5-4) below. A desirable ratio of the opticallyactive compound is approximately 5% by weight or less, and a moredesirable ratio thereof ranges from approximately 0.01% by weight toapproximately 2% by weight.

An antioxidant is mixed with the composition in order to avoid adecrease in specific resistance caused by heating in the air, or tomaintain a large voltage holding ratio at room temperature and also at ahigh temperature even after the device has been used for a long time.

Preferred examples of the antioxidant include the compound (6):

wherein n is an integer of from 1 to 9. In the compound (6), desirable nare 1, 3, 5, 7, or 9. More desirable n are 1 or 7. When n is 1, thecompound (6) has a large volatility, and is effective in preventing thedecrease of specific resistance caused by heating in the air. When n is7, the compound (6) has a small volatility, and is effective inmaintaining a large voltage holding ratio at room temperature and alsoat a high temperature even after the device has been used for a longtime. A desirable ratio of the antioxidant is approximately 50 ppm ormore for obtaining the advantage thereof and is approximately 600 ppm orless for preventing the maximum temperature from being decreased andpreventing the minimum temperature from being increased. A moredesirable ratio thereof ranges from approximately 100 ppm toapproximately 300 ppm.

Preferred examples of the ultraviolet light absorbent include abenzophenone derivative, a benzoate derivative and a triazolederivative. A light stabilizer, such as an amine having steric hindranceis also desirable. A desirable ratio of the absorbent and the stabilizeris approximately 50 ppm or more for obtaining the advantage thereof andis approximately 10,000 ppm or less for preventing the maximumtemperature from being decreased and preventing the minimum temperaturefrom being increased. A more desirable ratio thereof ranges fromapproximately 100 ppm to approximately 10,000 ppm.

A dichroic dye such as an azo dye or an anthraquinone dye is mixed withthe composition to suit for a device of a guest host (GH) mode. Adesirable ratio of the dye ranges from approximately 0.01% by weight toapproximately 10% by weight. A defoaming agent such as dimethyl siliconeoil or methylphenyl silicone oil is mixed with the composition. Adesirable ratio of the defoaming agent is approximately 1 ppm or morefor obtaining the advantage thereof and is approximately 1,000 ppm orless for preventing display failure from occurring. A more desirableratio thereof ranges from approximately 1 ppm to approximately 500 ppm.

Seventh, the preparation methods of the component compounds will beexplained. These compounds can be prepared by known methods. Thepreparation method will be exemplified below. The compounds (1-1-1) and(1-3-1) are prepared by the method disclosed in WO 2006-038522 A/2006.The compound (2-1) is prepared by the method disclosed in JP H2-5034431A/1990. The compound (3-1-4) is prepared by the method disclosed in JPH4-46934 B/1992. The compound (3-2-1) is prepared by the methoddisclosed in JP H2-501071 A/1990. The compound (4-1-1) is prepared bythe method disclosed in JP S54-106454A/1979. The compound (4-2-i) isprepared by the method disclosed in JP S57-165328 A/1982. The compound(4-2-2) is prepared by the method disclosed in JP H4-30382 B/1992. Thecompound (4-4-i) is prepared by the method disclosed in JP S60-51135A/1985. The antioxidant is commercially available. The compound (6),wherein n is 1, is available, for example, from Sigma-Aldrich, Inc. Thecompound (5), wherein n is 7, is prepared by the method disclosed inU.S. Pat. No. 3,660,505.

The compounds for which preparation methods were not described above canbe prepared according to the methods described in ORGANIC SYNTHESES(John Wiley & Sons, Inc.), ORGANIC REACTIONS (John Wiley & Sons, Inc.),COMPREHENSIVE ORGANIC SYNTHESIS (Pergamon Press), NEW EXPERIMENTALCHEMISTRY COURSE (Shin Jikken Kagaku Kouza) (Maruzen, Inc.), and soforth. The composition is prepared according to known methods using thecompounds thus obtained. For example, the component compounds are mixedand dissolved in each other by heating.

Last, use of the composition will be explained. Most of the compositionshave a minimum temperature of approximately −10° C. or less, a maximumtemperature of 70° C. or more, and an optical anisotropy ofapproximately 0.07 to approximately 0.20. The device containing thecomposition has a large voltage holding ratio. The composition issuitable for an AM device. The composition is suitable especially for anAM device of a transmission type. The composition having an opticalanisotropy of approximately 0.08 to approximately 0.25 and furtherhaving an optical anisotropy of approximately 0.10 to approximately 0.30may be prepared by controlling ratios of the component compounds or bymixing other liquid crystal compounds. The composition can be used as acomposition having a nematic phase and as an optically activecomposition by adding an optically active compound.

The composition can be used for an AM device. It can also be used for aPM device. The composition can also be used for an AM or device or a PMdevice having a mode such as PC, TN, STN, ECB, OCB, IPS, VA, and soforth. It is desirable to use the composition for an AM device having amode of VA or IPS. These devices may be of a reflection type, atransmission type or a semi-transmission type. It is desirable to usethe composition for a device of a transmission type. It can be used foran amorphous silicon-TFT device or a polycrystal silicon-TFT device. Thecomposition is also usable for a nematic curvilinear aligned phase(NCAP) device prepared by microcapsulating the composition, and for apolymer dispersed (PD) device in which a three dimensional net-workpolymer is formed in the composition.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the invention and specificexamples provided herein without departing from the spirit or scope ofthe invention. Thus, it is intended that the invention covers themodifications and variations of this invention that come within thescope of any claims and their equivalents.

The following examples are for illustrative purposes only and are notintended, nor should they be interpreted to, limit the scope of theinvention.

EXAMPLES

When a sample was a composition, it was measured as it was, and theobtained value is described here. When a sample was a compound, a samplefor measurement was prepared by mixing 15% by weight of the compound and85% by weight of mother liquid crystals. A value of characteristic ofthe compound was calculated by extrapolating from a value obtained bymeasurement. Namely: (extrapolated value)={(value measured)−0.85×(valuemeasured for mother liquid crystals)}/0.15. When a smectic phase (orcrystals) separated out at this ratio at 25° C., a ratio of the compoundand mother liquid crystals was changed step by step in the order of (10%by weight/90% by weight), (5% by weight/95% by weight), (1% byweight/99% by weight), respectively. Values for a maximum temperature,optical anisotropy, viscosity, and dielectric anisotropy of the compoundwere obtained by the extrapolation.

The composition of the mother liquid crystals is as shown below.

Measurement of the characteristics was carried out according to thefollowing methods. Most methods are described in the Standard ofElectric Industries Association of Japan, EIAJ.ED-2521 A or those withsome modifications.

Maximum Temperature of a Nematic Phase (NI; ° C.): A sample was placedon a hot plate in a melting point apparatus equipped with a polarizingmicroscope and was heated at the rate of 1° C. per minute. A temperaturewas measured when a part of the sample began to change from a nematicphase into an isotropic liquid. A higher limit of a temperature range ofa nematic phase may be abbreviated to “a maximum temperature.”

Minimum Temperature of a Nematic Phase (Tc; ° C.): A sample having anematic phase was put in a glass vial and then kept in a freezer attemperatures of 0° C., −10° C., −20° C., −30° C., and −40° C. for tendays, respectively, and a liquid crystal phase was observed. Forexample, when the sample remained in a nematic phase at −20° C. andchanged to crystals or a smectic phase at −30° C., Tc was expressed as≦−20° C. A lower limit of a temperature range of a nematic phase may beabbreviated to “a minimum temperature.”

Viscosity (η; measured at 20° C., mPa·s): A viscosity was measured bymeans of an E-type viscometer.

Optical Anisotropy (Δn; measured at 25° C.): Measurement was carried outwith an Abbe refractometer mounting a polarizing plate on an ocularusing a light at a wavelength of 589 nm. The surface of a main prism wasrubbed in one direction, and then a sample was dropped on the mainprism. The refractive index (n∥) was measured when the direction of apolarized light was parallel to that of the rubbing. The refractiveindex (n⊥) was measured when the direction of a polarized light wasperpendicular to that of the rubbing. A value of optical anisotropy wascalculated from the equation: Δn=n∥−n⊥.

Dielectric Anisotropy (Δε; measured at 25° C.): A value of a dielectricanisotropy was calculated from the equation: Δε=ε∥−ε⊥. The values ofdielectric anisotropy (ε∥ and ε⊥) were measured in the following manner.

(1) Measurement of dielectric anisotropy (ε∥): A solution ofoctadecyltriethoxysilane (0.16 mL) dissolved in ethanol (20 mL) wascoated on a glass substrate having been well cleaned. The glasssubstrate was rotated with a spinner and then heated to 150° C. for 1hour. A sample was charged in a VA device having a distance (cell gap)of 4 μm between two sheets of the glass substrates, and the device wassealed with an adhesive capable of being cured with ultraviolet light.Sine waves (0.5 V, 1 kHz) were applied to the device, and after lapsingtwo seconds, a dielectric constant (ε∥) in the major axis direction ofthe liquid crystal molecule was measured.

(2) Measurement of dielectric anisotropy (ε⊥): Polyimide was coated on aglass substrate having been well cleaned. The glass substrate was baked,and the resulting orientation film was subjected to a rubbing treatment.A sample was charged in a TN device having a distance between two sheetsof the glass substrates of 9 μm and a twisted angle of 80°. Sine waves(0.5 V, 1 kHz) were applied to the device, and after lapsing twoseconds, a dielectric constant (ε⊥) in the minor axis direction of theliquid crystal molecule was measured.

Threshold Voltage (Vth; measured at 25° C.; V): Measurement was carriedout with LCD Evaluation System Model LCD-5 100 made by OtsukaElectronics Co., Ltd. The light source was a halogen lamp. A sample waspoured into a VA device of a normally black mode, in which a cell gapbetween two glass plates was 4 μm, and a rubbing direction wasantiparallel, and the device was sealed with a UV curing adhesive. Thevoltage to be applied onto the device (60 Hz, rectangular waves) wasincreased stepwise by 0.02 V starting from 0 V up to 20 V During thestepwise increasing, the device was irradiated with light in aperpendicular direction, and an amount of the light passing through thedevice was measured. A voltage-transmission curve was prepared, in whicha maximum amount of a light corresponded to 100% transmittance, aminimum amount of a light corresponded to 0% transmittance. Thethreshold voltage is a value at 10% transmittance.

Voltage Holding Ratio (VHR-1; measured at 25° C.; %): A TN device usedfor measurement has a polyimide-alignment film and the cell gap betweentwo glass plates is 5 μm. A sample was poured into the device, and thenthe device was sealed with an adhesive which is polymerized by theirradiation of an ultraviolet light. The TN device was applied andcharged with pulse voltage (60 microseconds at 5 V). The decreasingvoltage was measured for 16.7 milliseconds with High Speed Voltmeter andthe area A between a voltage curve and a horizontal axis in a unit cyclewas obtained. The area B was an area without decreasing. The voltageholding ratio is a percentage of the area A to the area B.

Voltage Holding Ratio (VHR-2; measured at 80° C.; %): A TN device usedfor measurement has a polyimide-alignment film and the cell gap betweentwo glass plates is 5 μm. A sample was poured into the device, and thenthe device was sealed with an adhesive which is polymerized by theirradiation of an ultraviolet light. The TN device was applied andcharged with pulse voltage (60 microseconds at 5 V). The decreasingvoltage was measured for 16.7 milliseconds with High Speed Voltmeter andthe area A between a voltage curve and a horizontal axis in a unit cyclewas obtained. The area B was an area without decreasing. The voltageholding ratio is a percentage of the area A to the area B.

Voltage Holding Ratio (VHR-3; measured at 25° C.; %): After irradiatingwith ultraviolet light, a voltage holding ratio was measured to evaluatestability to ultraviolet light. A composition having large VHR-3 has alarge stability to ultraviolet light. A TN device used for measurementhas a polyimide-alignment film and the cell gap is 5 μm. A sample waspoured into the device, and then the device was irradiated with lightfor 20 minutes. The light source was a superhigh voltage mercury lampUSH-500D (produced by Ushio, Inc.), and the distance between the deviceand the light source is 20 cm. In measurement of VHR-3, a decreasingvoltage is measured for 16.7 milliseconds. A VHR-3 is desirably 90% ormore, and more desirably 95% or more.

Voltage Holding Ratio (VHR-4; measured at 25° C.; %): A voltage holdingratio was measured after heating an TN device having a sample pouredtherein in a constant-temperature bath at 80° C. for 500 hours toevaluate stability to heat. A composition having large VHR-4 has a largestability to heat. In measurement of VHR-4, a decreasing voltage ismeasured for 16.7 milliseconds.

Response Time (τ; measured at 25° C.; ms): Measurement was carried outwith LCD Evaluation System Model LCD-5100 made by Otsuka ElectronicsCo., Ltd. The light source is a halogen lamp. Low-pass filter was set at5 kHz. A sample was poured into a VA device of a normally black mode, inwhich a cell gap between two glass plates was 4 μm, and a rubbingdirection was antiparallel, and the device was sealed with a UV curingadhesive. Rectangle waves (60 Hz, 10 V, 0.5 seconds) were applied to thedevice. During application, the device was irradiated with light in aperpendicular direction, and an amount of the light passing through thedevice was measured. A maximum amount of a light corresponds to 100%transmittance, and a minimum amount of a light corresponds to 0%transmission. The rise time is a period of time required for the changein transmittance from 90% to 10% (fall time: ms).

Specific Resistance (ρ; measured at 25° C.; Ωcm): A 1.0 mL of a samplewas charged in a vessel equipped with electrodes. A direct currentvoltage of 10 V was applied to the vessel, and after lapsing 10 secondfrom the application of voltage, the direct electric current wasmeasured. The specific resistance was calculated by the equation:(specific resistance)={(voltage)×(electric capacity of vessel)}/{(directcurrent)×(dielectric constant of vacuum)}.

Gas Chromatographic Analysis: A Gas Chromatograph Model GC-14B made byShimadzu was used for measurement. The carrier gas was helium (2milliliters per minute). An evaporator and a detector (FID) were set upat 280° C. and 300° C., respectively. Capillary column DB-1 (length 30meters, bore 0.32 millimeters, film thickness 0.25 micrometers,dimethylpolysiloxane as stationary phase, no polarity) made by AgilentTechnologies, Inc. was used for the separation of the componentcompound. After the column had been kept at 200° C. for 2 minutes, itwas further heated to 280° C. at the rate of 5° C. per minute. A samplewas prepared in an acetone solution (0.1% by weight), and 1 microliterof the solution was injected into the evaporator. The recorder used wasChromatopac Model C-R5A made by Shimadzu or its equivalent. The gaschromatogram obtained showed a retention time of a peak and a peak areacorresponding to the component compound.

Solvents for diluting the sample may also be chloroform, hexane, and soforth. The following capillary columns may also be used: HP-1 made byAgilent Technologies Inc. (length 30 meters, bore 0.32 millimeters, filmthickness 0.25 micrometers), Rtx-1 made by Restek Corporation (length 30meters, bore 0.32 millimeters, film thickness 0.25 micrometers), andBP-1 made by SGE International Pty. Ltd. (length 30 meters, bore 0.32millimeters, film thickness 0.25 micrometers). In order to preventcompound peaks from overlapping, a capillary column CBP1-M50-025 (50meters, bore 0.25 millimeters, film thickness 0.25 micrometers) made byShimadzu Corporation may be used.

The ratios of the liquid crystal compounds contained in the compositioncan also be calculated in the following manner. A liquid crystalcompound can be detected by gas chromatography. An area ratio of peakson a gas chromatogram corresponds to a ratio (molar number) of liquidcrystal compounds. In the case where the aforementioned capillarycolumns are used, correction coefficients of the liquid crystalcompounds can be regarded as 1. Accordingly, the ratio (% by weight) ofliquid crystal compounds is calculated from the area ratio of peaks.

The invention will be explained in detail by way of Examples. Theinvention is not limited by the Examples described below. The compoundsdescribed in the Comparative Examples and the Examples are expressed bythe symbols according to the definition in Table 3. In Table 3, theconfiguration of 1,4-cyclohexylene is trans. The parenthesized numbernext to the symbolized compounds in the Examples corresponds to thenumber of the desirable compound. The symbol (−) means other liquidcrystal compound. A ratio (percentage) of a liquid crystal compositionis percentage by weight (% by weight) based on the total weight of aliquid crystal composition, and the liquid crystal composition containsimpurities in addition to the compounds described. Finally, thecharacteristics of the compositions are described.

TABLE 3 Method of Description of Compound using Symbols. R—(A₁)—Z₁—- - -—Z_(n)—(A_(n))—R′ 1) Left Terminal Group R— Symbol C_(n)H_(2n+1)— n-C_(n)H_(2n+1)O— nO- C_(m)H_(2m+1)OC_(n)H_(2n)— mOn- CH₂═CH— V-C_(n)H_(2n+1)CH═CH— nV- CH₂═CH—C_(n)H_(2n)— Vn-C_(m)H_(2m+1)—CH═CH—C_(n)H_(2n)— mVn- CH₂═CH—C₂H₄—CH═CH—C₂H₄— V2V2-CF₂═CH— VFF- CF₂═CH—C₂H₄— VFF2- 2) Right Terminal Group —R′ Symbol—C_(n)H_(2n+1) -n —OC_(n)H_(2n+1) -On —CH═CH₂ -V —CH═CHC_(n)H_(2n+1) -Vn—C_(n)H_(2n)CH═CH₂ -nV —CH═CF₂ -VFF —COO—CH₃ -EME 3) Bonding group -Zn-Symbol —C₂H₄—  2 —COO— E —CH═CH— V —CH₂O— 10 4) Ring Structure -An-Symbol

H

B

B(F)

B(2F)

B(2F,5F)

B(2F,3F)

B(2F,3Cl)

B(2Cl,3F)

dh 5) Example of Description Example 1 3-Hdh-V

Example 2 1V2-HBB(2F,3F)-O2

Example 3 3-HBB(2F,3Cl)-O2

Example 4 2-BB(F)B-3

Comparative Example 1

The following composition claimed in JP H11-140447 A/1999 were preparedand measured for characteristics.

3-HB(2F,3F)-O2 (2-1) 15% 5-HB(2F,3F)-O2 (2-1) 15% 3-HHB(2F,3F)-O2(3-1-1) 10% 5-HHB(2F,3F)-O2 (3-1-1) 10% 2-HHB(2F,3F)-1 (3-1-1) 10%3-HHB(2F,3F)-1 (3-1-1) 10% V-HHB-1 (4-2-2) 5% 2-BB(F)B-3 (4-4-1) 5%V-HH-3 (—) 20%

NI=79.3° C.; Tc≦−20° C.; Δn=0.091; Δε=−3.3; η=20.0 mPa·s; Vth=2.19 V;VHR-1=99.0%; VHR-2=98.7%; VHR-3=98.8%; VHR-4=98.6%.

Comparative Example 2

WO 2006-038522 A/2006 discloses the composition example 9 as a negativecomposition containing a compound having a skeleton similar to the firstcomponent of the invention, a compound of the second component of theinvention, and a compound of the third component of the invention.

5-Hdh2H-2 (—) 4% 2-HdhH-3 (—) 4% 3-HB(2F,3F)-O2 (2-1) 10% 5-HB(2F,3F)-O2(2-1) 10% 2-HHB(2F,3F)-1 (3-1-1) 4% 3-HHB(2F,3F)-2 (3-1-1) 4%3-HHB(2F,3F)-O2 (3-1-1) 12% 5-HHB(2F,3F)-O2 (3-1-1) 10% 3-HHEH-3 (4-1-1)4% 3-HHEH-5 (4-1-1) 3% 4-HHEH-3 (4-1-1) 3% 3-HH-4 (—) 5% 3-HH-5 (—) 5%3-HH-O1 (—) 6% 3-HH-O3 (—) 6% 3-HB-O1 (—) 5% 3-HB-O2 (—) 5%

NI=85.6° C.; Tc≦0° C.; Δn=0.075; η=27.4 mPa·s; Δε=−3.3.

Example 1

The composition of Example 1 had an equivalent maximum temperature, aparticularly low minimum temperature and a negatively low Δε, ascompared to the composition of Comparative Example 1.

3-Hdh-V (1-1-1) 16% 3-HB(2F,3F)-O2 (2-1) 15% 5-HB(2F,3F)-O2 (2-4) 15%3-HHB(2F,3F)-O2 (3-1-1) 10% 5-HHB(2F,3F)-O2 (3-1-1) 10% 2-HHB(2F,3F)-1(3-1-1) 10% 3-HHB(2F,3F)-1 (3-1-1) 10% V-HHB-1 (4-2-2) 9% 2-BB(F)B-3(4-4-1) 5%

NI=80.3° C.; Tc≦−40° C.; Δn=0.094; Δε=−3.8; η=25.2 mPa·s; Vth=2.10 V;VHR-1=99.1%; VHR-2=98.7%; VHR-3=98.8%; VHR-4=98.6%.

Example 2

The composition of Example 2 had an equivalent maximum temperature, aparticularly low minimum temperature and a negatively low Δε, ascompared to the composition of Comparative Example 2.

3-BHdh-V (1-3-1) 9% 3-BHdh-3 (1-3-1) 5% 3-HB(2F,3F)-O2 (2-1) 15%5-HB(2F,3F)-O2 (2-1) 13% 3-HHB(2F,3F)-O2 (3-1-1) 10% 5-HHB(2F,3F)-O2(3-1-1) 10% 2-HHB(2F,3F)-1 (3-1-1) 10% 3-HHB(2F,3F)-1 (3-1-1) 10% 2-HH-5(—) 5% V-HH-3 (—) 10% 3-HB-O2 (—) 3%

NI=85.4° C.; Tc≦−20° C.; Δn=0.085; η=26.1 mPa·s; Δε=−3.6.

Example 3

3-Hdh-V (1-1-1) 25% 3-Hdh-1V (1-1-1) 5% 3-HB(2F,3F)-O2 (2-1) 10%5-HB(2F,3F)-O2 (2-1) 11% 1V2-HB(2F,3F)-O2 (2-1) 5% 3-HHB(2F,3F)-O2(3-1-1) 11% 5-HHB(2F,3F)-O2 (3-1-1) 6% 1V2-HHB(2F,3F)-O2 (3-1-1) 5%2-HHB(2F,3F)-1 (3-1-1) 11% 3-HHB(2F,3F)-1 (3-1-1) 11%

NI=70.2° C.; Tc≦−40° C.; Δn=0.079; Δε=−3.5; η=25.4 mPa·s; VHR-1=99.0%;VHR-2=98.5%; VHR-3=98.8%.

Example 4

3-Hdh-V (1-1-1) 14% 3-HB(2F,3F)-O2 (2-1) 14% 5-HB(2F,3F)-O2 (2-1) 14%3-HHB(2F,3F)-O2 (3-1-1) 11% 5-HHB(2F,3F)-O2 (3-1-1) 11% 2-HHB(2F,3F)-1(3-1-1) 10% 3-HHB(2F,3F)-1 (3-1-1) 10% 2-BB(F)B-3 (4-4-1) 8% 2-BB(F)B-5(4-4-1) 4% 1-BB(F)B-2V (4-4-1) 4%

NI=84.2° C.; Tc≦−30° C.; Δn=0.114; Δε=−3.7; η=29.4 mPa·s.

Example 5

3-Hdh-V (1-1-1) 15% 5-Hdh-V (1-1-1) 5% 3-HB(2F,3F)-O2 (2-1) 15%5-HB(2F,3F)-O2 (2-1) 15% 3-HHB(2F,3F)-O2 (3-1-1) 10% 5-HHB(2F,3F)-O2(3-1-1) 10% 2-HHB(2F,3F)-1 (3-1-1) 10% 3-HHB(2F,3F)-1 (3-1-1) 10%3-HHEH-3 (4-1-1) 3% 3-HHEH-5 (4-1-1) 3% 4-HHEH-3 (4-1-1) 4%

NI=80.9° C.; Tc≦−40° C.; Δn=0.081; Δε=−3.9; η=25.3 mPa·s.

Example 6

3-Hdh-V (1-1-1) 10% 3-HB(2F,3F)-O2 (2-1) 15% 5-HB(2F,3F)-O2 (2-1) 13%3-HHB(2F,3F)-O2 (3-1-1) 10% 5-HHB(2F,3F)-O2 (3-1-1) 10% 2-HHB(2F,3F)-1(3-1-1) 10% 3-HHB(2F,3F)-1 (3-1-1) 10% 3-HHB-3 (4-2-1) 7% 2-HH-5 (—) 5%3-HB-O2 (—) 5% 5-HB-O2 (—) 5%

NI=76.3° C.; Tc≦−30° C.; Δn=0.085; Δε=−3.4; VHR-1=99.2%; VHR-2=98.9%;VHR-3=98.2%.

Example 7

3-Hdh-V (1-1-1) 10% 3-HB(2F,3Cl)-O2 (2-3) 12% 5-HB(2F,3Cl)-O2 (2-3) 12%3-HHB(2F,3Cl)-O2 (3-1-7) 8% 5-HHB(2F,3Cl)-O2 (3-1-7) 8% 3-HBB(2F,3Cl)-O2(3-1-10) 15% 5-HBB(2F,3Cl)-O2 (3-1-10) 15% 2-BB(F)B-3 (4-4-1) 10%2-BB(F)B-5 (4-4-1) 10%

NI=97.3° C.; Tc≦−30° C.; Δn=0.144; Δε=−3.5.

Example 8

3-Hdh-V (1-1-1) 10% 3-Hdh-VFF (1-1-1) 8% 3-HB(2F,3Cl)-O2 (2-3) 15%5-HB(2F,3Cl)-O2 (2-3) 14% 3-HHB(2F,3Cl)-O2 (3-1-7) 5% 4-HHB(2F,3Cl)-O2(3-1-7) 5% 5-HHB(2F,3Cl)-O2 (3-1-7) 5% 3-HBB(2F,3Cl)-O2 (3-1-10) 10%5-HBB(2F,3Cl)-O2 (3-1-10) 10% V2-HHB-1 (4-2-2) 4% 3-HH-4 (—) 8% V-HH-3(—) 6%

NI=70.1° C.; Tc≦−30° C.; Δn=0.085; Δε=−3.0; η=35.9 mPa·s; VHR-1=98.7%;VHR-2=98.2%; VHR-3=98.3%.

Example 9

3-Hdh-V (1-1-1) 15% 5-Hdh-1V (1-1-1) 5% 3-HB(2F,3F)-O2 (2-1) 15%5-HB(2F,3F)-O2 (2-1) 15% 3-HBB(2F,3F)-O2 (3-1-4) 15% 5-HBB(2F,3F)-O2(3-1-4) 15% V-HH-3 (—) 3% 1V-HH-3 (—) 10% 5-HBB(F)B-2 (—) 4% 5-HBB(F)B-3(—) 3%

NI=81.6° C.; Tc≦−40° C.; Δn=0.111; Δε=−3.4; η=21.1 mPa·s; Vth=2.29 V;VHR-1=98.8%; VHR-2=98.2%; VHR-3=98.2%.

Example 10

3-Hdh-V (1-1-1) 15% 5-Hdh-1V (1-1-1) 5% 3-HB(2F,3F)-O2 (2-1) 15%5-HB(2F,3F)-O2 (2-1) 15% 3-HBB(2F,3F)-O2 (3-1-4) 15% 5-HBB(2F,3F)-O2(3-1-4) 15% V-HH-3 (—) 8% VFF-HH-3 (—) 3% 3-HHEBH-3 (—) 3% 3-HHEBH-5 (—)3% 5-HB(F)BH-3 (—) 3%

NI=82.2° C.; Tc≦−40° C.; Δn=0.101; Δε=−3.4; η=21.9 mPa·s; Vth=2.25 V.

Example 11

3-Hdh-2 (1-1-1) 6% 5-Hdh-2 (1-1-1) 10% 3-HB(2F,3F)-O2 (2-1) 15%5-HB(2F,3F)-O2 (2-1) 15% 3-HHB(2F,3F)-O2 (3-1-1) 10% 5-HHB(2F,3F)-O2(3-1-1) 10% 2-HHB(2F,3F)-1 (3-1-1) 10% 3-HHB(2F,3F)-1 (3-1-1) 10%V-HHB-1 (4-2-2) 5% VFF-HHB-1 (4-2-2) 4% 2-BB(F)B-3 (4-4-1) 5%

NI=80.1° C.; Tc≦−30° C.; Δn=0.091; Δε=−3.7; η=24.5 mPa·s; Vth=2.18 V.

Example 12

3-Hdh-2 (1-1-1) 10% 5-Hdh-2 (1-1-1) 10% 3-Hdh-O1 (1-1-1) 10%3-HB(2F,3F)-O2 (2-1) 14% 5-HB(2F,3F)-O2 (2-1) 12% 3-HHB(2F,3F)-O2(3-1-1) 11% 5-HHB(2F,3F)-O2 (3-1-1) 11% 2-HHB(2F,3F)-1 (3-1-1) 11%3-HHB(2F,3F)-1 (3-1-1) 11%

NI=70.0° C.; Tc≦−30° C.; Δn=0.072; Δε=−3.3; Vth=1.59 V; VHR-1=98.9%;VHR-2=98.2%; VHR-3=98.5%.

Example 13

3-HVdh-3 (1-1-3) 14% 3-HB(2F,3F)-O2 (2-1) 14% 5-HB(2F,3F)-O2 (2-1) 14%3-HHB(2F,3F)-O2 (3-1-1) 11% 5-HHB(2F,3F)-O2 (3-1-1) 11% 2-HHB(2F,3F)-1(3-1-1) 10% 3-HHB(2F,3F)-1 (3-1-1) 10% 2-BBB(2F)-5 (4-4-2) 4%5-BBB(2F)-2 (4-4-2) 4% 2-BB(2F,5F)B-2 (4-4-3) 4% 2-BB(2F,5F)B-3 (4-4-3)4%

NI=84.8° C.; Tc≦−30° C.; Δn=0.113; Δε=−3.6; η=30.2 mPa·s; Vth=2.20 V.

Example 14

V-dhH-3 (1-2-1) 20% 3-HB(2F,3F)-O2 (2-1) 15% 5-HB(2F,3F)-O2 (2-1) 15%3-HHB(2F,3F)-O2 (3-1-1) 10% 5-HHB(2F,3F)-O2 (3-1-1) 10% 2-HHB(2F,3F)-1(3-1-1) 10% 3-HHB(2F,3F)-1 (3-1-1) 10% 3-HHEH-3 (4-1-1) 3% 3-HHEH-5(4-1-1) 3% 3-HH1OH-3 (4-1-2) 4%

NI=81.1° C.; Tc≦−30° C.; Δn=0.081; Δε=−3.8; η=24.9 mPa·s; Vth=2.00 V;VHR-1=99.0%; VHR-2=98.4%; VHR-3=98.7%.

Example 15

V-dhH-3 (1-2-1) 10% V-dhH-5 (1-2-1) 10% 3-HB(2F,3F)-O2 (2-1) 15%5-HB(2F,3F)-O2 (2-1) 15% 3-HHB(2F,3F)-O2 (3-1-1) 10% 5-HHB(2F,3F)-O2(3-1-1) 10% 2-HHB(2F,3F)-1 (3-1-1) 10% 3-HHB(2F,3F)-1 (3-1-1) 10%V-HHB-1 (4-2-2) 5% 2-BB(F)B-3 (4-4-1) 5%

NI=74.9° C.; Tc≦−30° C.; Δn=0.091; Δε=−3.7; η=24.9 mPa·s; Vth=2.02 V.

Example 16

3-Bdh-2 (1-1-4) 10% 2O-Bdh-3 (1-1-4) 6% 3-HB(2F,3F)-O2 (2-1) 15%5-HB(2F,3F)-O2 (2-1) 15% 3-HHB(2F,3F)-O2 (3-1-1) 10% 5-HHB(2F,3F)-O2(3-1-1) 10% 2-HHB(2F,3F)-1 (3-1-1) 10% 3-HHB(2F,3F)-1 (3-1-1) 10%V-HHB-1 (4-2-2) 9% 2-BB(F)B-3 (4-4-1) 5%

NI=74.1° C.; Tc≦−30° C.; Δn=0.094; Δε=−3.6; η=26.0 mPa·s; Vth=1.99 V;VHR-1=99.0%; VHR-2=98.6%; VHR-3=98.7%.

Example 17

3-Bdh-2 (1-1-4) 5% 3-B2dh-2 (1-1-5) 5% 3-HB(2F,3F)-O2 (2-1) 15%5-HB(2F,3F)-O2 (2-1) 13% 3-HHB(2F,3F)-O2 (3-1-1) 10% 5-HHB(2F,3F)-O2(3-1-1) 10% 2-HHB(2F,3F)-1 (3-1-1) 10% 3-HHB(2F,3F)-1 (3-1-1) 10%3-HHB-3 (4-2-1) 3% 3-HHB-O1 (4-2-1) 4% 3-HH-EME (—) 5% 3-HB-O2 (—) 5%5-HB-O2 (—) 5%

NI=72.3° C.; Tc≦−30° C.; Δn=0.085; Δε=−3.5; VHR-1=99.0%; VHR-2=98.5%;VHR−3=98.5%.

Example 18

3-Bdh-2 (1-1-4) 5% 5-Bdh-2 (1-1-4) 5% 3-dhB-2 (1-2-4) 10% 3-HB(2F,3F)-O2(2-1) 15% 5-HB(2F,3F)-O2 (2-1) 10% 3-HB(2F,3F)-O4 (2-1) 5%3-HBB(2F,3F)-O2 (3-1-4) 15% 5-HBB(2F,3F)-O2 (3-1-4) 15% 1V-HH-3 (—) 13%5-HBB(F)B-2 (—) 4% 5-HBB(F)B-3 (—) 3%

NI=72.8° C.; Tc≦−30° C.; Δn=0.105; Δε=−3.2; η=20.7 mPa·s; Vth=2.05 V;VHR-1=99.1%; VHR-2=98.6%; VHR-3=98.2%.

Example 19

3-Hdh-V (1-1-1) 10% 1V-Hdh-V (1-1-1) 20% 3-HB(2F,3F)-O2 (2-1) 14%5-HB(2F,3F)-O2 (2-1) 12% 3-HHB(2F,3F)-O2 (3-1-1) 11% 5-HHB(2F,3F)-O2(3-1-1) 11% 2-HHB(2F,3F)-1 (3-1-1) 11% 3-HHB(2F,3F)-1 (3-1-1) 5% V-HHB-1(4-2-2) 3% 2-BB(F)B-3 (4-4-1) 3%

NI=73.2° C.; Tc≦−30° C.; Δn=0.089; Δε=−3.1; η=29.0 mPa·s.

Example 20

3-H2dh-2 (1-1-2) 7% 3-dhH-O1 (1-2-1) 7% 3-HB(2F,3F)-O2 (2-1) 14%5-HB(2F,3F)-O2 (2-1) 14% 3-HHB(2F,3F)-O2 (3-1-1) 11% 5-HHB(2F,3F)-O2(3-1-1) 11% 2-HHB(2F,3F)-1 (3-1-1) 10% 3-HHB(2F,3F)-1 (3-1-1) 10%3-HBB-2 (4-3-1) 4% 1V2-HBB-2 (4-3-2) 4% 2-BB(F)B-3 (4-4-1) 8%

NI=86.7° C.; Tc≦−30° C.; Δn=0.110; Δε=−3.6; η=31.0 mPa·s; Vth=2.22 V;VHR-1=98.9%; VHR-2=98.4%; VHR-3=98.3%.

Example 21

1V-Hdh-V (1-1-1) 8% V-dhH-3 (1-2-1) 10% 3-HB(2F,3Cl)-O2 (2-3) 15%5-HB(2F,3Cl)-O2 (2-3) 7% 3-HB(2C1,3F)-O2 (2-5) 7% 3-HHB(2F,3Cl)-O2(3-1-7) 5% 4-HHB(2F,3Cl)-O2 (3-1-7) 5% 5-HHB(2F,3Cl)-O2 (3-1-7) 5%3-HBB(2F,3Cl)-O2 (3-1-10) 10% 5-HBB(2F,3Cl)-O2 (3-1-10) 10% V2-HHB-1(4-2-2) 4% 3-HH-4 (—) 8% V-HH-3 (—) 6%

NI=70.9° C.; Tc≦−30° C.; Δn=0.087; Δε=−3.0; η=35.9 mPa·s; Vth=2.07 V;VHR-1=98.7%; VHR-2=98.4%; VHR-3=98.4%.

Example 22

3-Hdh-V (1-1-1) 16% 3-H2B(2F,3F)-O2 (2-2) 15% 5-H2B(2F,3F)-O2 (2-2) 15%2-HHB(2F,3F)-1 (3-1-1) 9% 3-HHB(2F,3F)-1 (3-1-1) 8% 3-HBB(2F,3F)-O2(3-1-4) 10% 5-HBB(2F,3F)-O2 (3-1-4) 10% V-HHB-1 (4-2-2) 9% 2-BB(F)B-3(4-4-1) 5% 5-HBB(F)B-2 (—) 3%

NI=84.7° C.; Tc≦−40° C.; Δn=0.097; Δε=−3.8; η=22.0 mPa·s; Vth=2.10 V;VHR-1=99.3%; VHR-2=98.6%; VHR-3=98.7%.

Example 23

3-Hdh-V (1-1-1) 10% 3-Hdh-1V (1-1-1) 4% 3-HB(2F,3F)-O2 (2-1) 4%5-HB(2F,3F)-O2 (2-1) 4% 3-H2B(2F,3F)-O2 (2-2) 10% 5-H2B(2F,3F)-O2 (2-2)10% 2-HHB(2F,3F)-1 (3-1-1) 5% 3-HHB(2F,3F)-1 (3-1-1) 5% 3-HH2B(2F,3F)-O2(3-1-2) 11% 5-HH2B(2F,3F)-O2 (3-1-2) 11% 3-HBB(2F,3F)-O2 (3-1-4) 5%5-HBB(2F,3F)-O2 (3-1-4) 5% 2-BB(F)B-3 (4-4-1) 8% 2-BB(F)B-5 (4-4-1) 8%

NI=89.7° C.; Tc≦−30° C.; Δn=0.122; Δε=−3.7; η=31.6 mPa·s; Vth=2.15 V;VHR-1=99.0%; VHR-2=98.3%; VHR-3=98.4%.

Example 24

3-Hdh-V (1-1-1) 15% 5-Hdh-1V (1-1-1) 5% 3-HB(2F,3F)-O2 (2-1) 15%5-HB(2F,3F)-O2 (2-1) 10% 3-HB(2F,3F)-O4 (2-1) 5% 3-HBB(2F,3F)-O2 (3-1-4)15% 5-HBB(2F,3F)-O2 (3-1-4) 15% 3-HH-O1 (—) 5% V-HH-V1 (—) 5% 7-HB-1 (—)3% 3-HEB-O2 (—) 3% 1O1-HBBH-3 (—) 4%

NI=70.4° C.; Tc≦−40° C.; Δn=0.104; Δε=−3.3; η=20.2 mPa·s; Vth=2.02 V;VHR-1=98.9%; VHR-2=98.5%; VHR-3=98.5%.

Example 25

3-Hdh-V (1-1-1) 10% 3-HB(2F,3F)-O2 (2-1) 10% 5-HB(2F,3F)-O2 (2-1) 10%3-HB(2F,3F)-O4 (2-1) 10% 3-HBB(2F,3F)-O2 (3-1-4) 19% 5-HBB(2F,3F)-O2(3-1-4) 19% 2-BB(F)B-3 (4-4-1) 8% 5-HBB(F)B-2 (—) 7% 5-HBB(F)B-3 (—) 7%

NI=106.8° C.; Tc≦−30° C.; Δn=0.153; Δε=−3.8.

Example 26

3-Hdh-V (1-1-1) 8% 3-BdhH-3 (1-5-1) 5% 3-HdhB-3 (1-6-1) 5%3-HB(2F,3F)-O2 (2-1) 10% 5-HB(2F,3F)-O2 (2-1) 10% 2-HHB(2F,3F)-1 (3-1-1)4% 3-HHB(2F,3F)-2 (3-1-1) 4% 3-HHB(2F,3F)-O2 (3-1-1) 12% 5-HHB(2F,3F)-O2(3-1-1) 10% 3-HHEH-3 (4-1-1) 4% 3-HHEH-5 (4-1-1) 3% 4-HHEH-3 (4-1-1) 3%3-HH-4 (—) 5% 3-HH-5 (—) 5% 3-HH-O1 (—) 6% 3-HH-O3 (—) 6%

NI=86.0° C.; Tc≦−20° C.; Δn=0.077; η=27.2 mPa·s; Δε=−3.5.

Example 27

3-Hdh-V (1-1-1) 16% 3-BHdh-V (1-3-1) 4% V-dhHB-3 (1-4-1) 5%3-HB(2F,3F)-O2 (2-1) 15% 5-HB(2F,3F)-O2 (2-1) 15% 3-HHB(2F,3F)-O2(3-1-1) 10% 5-HHB(2F,3F)-O2 (3-1-1) 10% 2-HHB(2F,3F)-1 (3-1-1) 10%3-HHB(2F,3F)-1 (3-1-1) 10% 2-BB(F)B-3 (4-4-1) 5%

NI=80.2° C.; Tc≦−30° C.; Δn=0.094; Δε=−3.8; η=26.6 mPa·s; Vth=2.05 V;VHR-1=99.0%.

Example 28

3-Hdh-V (1-1-1) 10% 3-Hdh-1V (1-1-1) 4% 3-BBdh-2V1 (1-3-5) 4% 1V2-dhBB-3(1-4-5) 4% 3-HB(2F,3F)-O2 (2-1) 4% 5-HB(2F,3F)-O2 (2-1) 4%3-H2B(2F,3F)-O2 (2-2) 10% 5-H2B(2F,3F)-O2 (2-2) 10% 2-HHB(2F,3F)-1(3-1-1) 5% 3-HHB(2F,3F)-1 (3-1-1) 5% 3-HH2B(2F,3F)-O2 (3-1-2) 11%5-HH2B(2F,3F)-O2 (3-1-2) 11% 3-HBB(2F,3F)-O2 (3-1-4) 5% 5-HBB(2F,3F)-O2(3-1-4) 5% 2-BB(F)B-3 (4-4-1) 8%

NI=92.5° C.; Tc≦−30° C.; Δn=0.116; Δε=−3.7; η=31.3 mPa·s.

Although the invention has been described and illustrated with a certaindegree of particularity, it is understood that the disclosure has beenmade only by way of example, and that numerous changes in the conditionsand order of steps can be resorted to by those skilled in the artwithout departing from the spirit and scope of the invention.

1. A liquid crystal composition having a negative dielectric anisotropy comprising three components, wherein the first component is at least one compound selected from the group of compounds represented by Formulas (1-1) to (1-6), the second component is at least one compound selected from the group of compounds represented by Formula (2), and the third component is at least one compound selected from the group of compounds represented by Formulas (3-1) and (3-2):

wherein R¹ and R² are each independently alkyl having 1 to 12 carbons, alkoxy having from 1 to 12 carbons, alkenyl having 2 to 12 carbons or alkenyl having 2 to 12 carbons, arbitrary hydrogen of which are replaced by fluorine; R³ to R⁵ are each independently alkyl having 1 to 12 carbons, alkoxy having from 1 to 12 carbons, alkenyl having 2 to 12 carbons or alkenyl having 2 to 12 carbons, arbitrary hydrogen of which are replaced by fluorine; X¹ and X² are each independently fluorine or chlorine, provided that at least one of X¹ and X² is fluorine; Z¹ and Z² are each independently a single bond, —CH₂CH₂— or —CH═CH—; Z³ to Z⁶ are each independently a single bond or —CH₂CH₂—; and ring A, ring B, ring C and ring D are each independently 1,4-cyclohexylene or 1,4-phenylene.
 2. The liquid crystal composition according to claim 1, wherein the first component is at least one compound selected from the group of compounds represented by Formulas (1-1) and (1-2), and the third component is at least one compound selected from the group of compounds represented by Formula (3-1).
 3. The liquid crystal composition according to claim 1, wherein the first component is at least one compound selected from the group of compounds represented by Formulas (1-3) to (1-6), and the third component is at least one compound selected from the group of compounds represented by Formula (3-1).
 4. The liquid crystal composition according to claim 1, wherein the ratio of the first component is from approximately 10% by weight to approximately 40% by weight, the ratio of the second component is from approximately 15% by weight to approximately 40% by weight, and the ratio of the third component is from approximately 20% by weight to approximately 50% by weight, based on the total weight of the liquid crystal composition.
 5. A liquid crystal composition having a negative dielectric anisotropy comprising three components, wherein the first component is at least one compound selected from the group of compounds represented by Formulas (1-1-A) to (1-6-A), the second component is at least one compound selected from the group of compounds represented by Formula (2-A), and the third component is at least one compound selected from the group of compounds represented by Formulas (3-1-A) and (3-2-A):

wherein R¹ and R² are each independently alkyl having 1 to 12 carbons, alkoxy having from 1 to 12 carbons, alkenyl having 2 to 12 carbons or alkenyl having 2 to 12 carbons, arbitrary hydrogen of which are replaced by fluorine; R³ to R⁵ are each independently alkyl having 1 to 12 carbons, alkoxy having from 1 to 12 carbons, alkenyl having 2 to 12 carbons or alkenyl having 2 to 12 carbons, arbitrary hydrogen of which are replaced by fluorine; Z¹ is a single bond, —CH₂CH₂— or —CH═CH—; Z³ and Z⁴ are each independently a single bond or —CH₂CH₂—; and ring B and ring D are each independently 1,4-cyclohexylene or 1,4-phenylene.
 6. The liquid crystal composition according to claim 5, wherein the second component is at least one compound selected from the group of compounds represented by formula (2-A); in Formula (2-A), R³ is alkyl having 1 to 12 carbons or alkenyl having 2 to 12 carbons, and R⁴ is alkoxy having 1 to 12 carbons; in Formula (3-1-A), R³ is alkyl having 1 to 12 carbons or alkenyl having 2 to 12 carbons, R⁴ is alkoxy having 1 to 2 carbons; and in Formula (3-2-A), R³ and R⁵ are each independently alkyl having 1 to 12 carbons.
 7. The liquid crystal composition according to claim 6, wherein in Formulas (1-1-A) to (1-6-A), Z¹ is a single bond, one of R¹ and R² is alkyl having 1 to 12 carbons, and the other is alkenyl having 2 to 12 carbons.
 8. The liquid crystal composition according to claim 7, wherein the first component is at least one compound selected from the group of compounds represented by Formulas (1-1-A) and (1-2-A), and the third component is at least one compound selected from the group of compounds represented by Formula (3-1-A).
 9. The liquid crystal composition according to claim 7, wherein the first component is at least one compound selected from the group of compounds represented by Formulas (1-3-A) to (1-6-A), and the third component is at least one compound selected from the group of compounds represented by Formula (3-1-A).
 10. The liquid crystal composition according to claim 7, wherein the first component is a mixture of at least one compound selected from the group of compounds represented by Formulas (1-1-A) and (1-2-A) and at least one compound selected from the group of compounds represented by Formulas (1-3-A) to (1-6-A), and the third component is at least one compound selected from the group of compounds represented by Formula (3-1-A).
 11. The liquid crystal composition according to claim 5, wherein the ratio of the first component is from approximately 10% by weight to approximately 40% by weight, the ratio of the second component is from approximately 15% by weight to approximately 40% by weight, and the ratio of the third component is from approximately 20% by weight to approximately 50% by weight, based on the total weight of the liquid crystal composition.
 12. The liquid crystal composition according to claims 5, wherein the composition further comprises at least one compound selected from the group of compounds represented by Formulas (4-1-A) to (4-4-A) as a fourth component:

wherein R⁶ to R¹¹ are each independently alkyl having 1 to 12 carbons, alkoxy having from 1 to 12 carbons, alkenyl having 2 to 12 carbons or alkenyl having 2 to 12 carbons, arbitrary hydrogen of which are replaced by fluorine; X³, X⁴ and X⁵ are each independently fluorine or hydrogen, provided that at least one of X³, X⁴ and X⁵ is fluorine; and Z⁷ is —COO— or —CH₂O—.
 13. The liquid crystal composition according to claim 12, wherein in Formula (4-1-A), R⁶ and R⁷ are alkyl having 1 to 12 carbons, and Z⁷ is —COO—; in Formulas (4-2-A) and (4-3-A), R⁸ is alkenyl having 2 to 12 carbons, and R⁹ is alkyl having 1 to 12 carbons; and in Formula (4-4-A), R¹⁰ and R¹¹ are each independently alkyl having 1 to 12 carbons or alkenyl having 2 to 12 carbons, X³ is fluorine, and X⁴ and X⁵ are hydrogen.
 14. The liquid crystal composition according to claim 12, wherein the fourth component is at least one compound selected from the group of compounds represented by Formula (4-2-A).
 15. The liquid crystal composition according to claim 12, wherein the fourth component is at least one compound selected from the group of compounds represented by Formula (4-4-A).
 16. The liquid crystal composition according to claims 12, wherein the ratio of the first component is from approximately 10% by weight to approximately 40% by weight, the ratio of the second component is from approximately 15% by weight to approximately 40% by weight, the ratio of the third component is from approximately 20% by weight to approximately 50% by weight, and the ratio of the fourth component is from approximately 5% by weight to approximately 30% by weight, based on the total weight of the liquid crystal composition.
 17. The liquid crystal composition according to claim 1, wherein the composition has a maximum temperature of a nematic phase of approximately 70° C. or more, a dielectric anisotropy (25° C.) at a frequency of 1 kHz of from approximately −6.0 to approximately −3.0, and a refractive index anisotropy (25° C.) at a wavelength of 589 nm of from approximately 0.08 to approximately 0.13.
 18. A liquid display device that includes the liquid crystal composition according to claim
 1. 19. The liquid crystal display device according to claim 18, wherein the liquid crystal display device has an operation mode of a VA mode or an IPS mode, and has a driving mode of an active matrix mode. 